Thermoelectric device and method of fabricating the same

ABSTRACT

A plurality of n-type bar-shaped devices ( 51 ) consisting of an n-type thermoelectric semiconductor and a plurality of p-type bar-shaped devices ( 52 ) consisting of a p-type thermoelectric semiconductor are regularly disposed or fixed through an insulating layer ( 50 ) to form a thermoelectric device block ( 53 ). End portions of the n-type bar shaped device ( 51 ) and the p-type bar-shaped device ( 52 ) are connected with an interconnection conductor ( 58   a ) on an upper surface ( 53   a ) and a lower surface ( 53   b ), which will be interconnecting end faces of the thermoelectric device block ( 53 ), to form a plurality of thermocouples connected in series. In addition, a pair of terminal conductors ( 58   b   , 58   b ) which is electrically connected with bar-shaped devices ( 51   a   , 52   a ) at least on one end portion and the other end portion of the n-type and p-type bar-shaped devices ( 51, 52 ) connected in series is formed on end face ( 53   c ) excluding the upper surface ( 53   a ) and the lower surface ( 53   b ) which will be an interconnecting end face of the thermoelectric device block ( 53 ), and a lead wire is connected to the terminal conductors ( 58   b   , 58   b ).

This application is a division of prior application Ser. No. 09/269,199filed Mar. 30 1999, which is a national stage application under §371 ofinternational application PCT/JP98/03447 filed Aug. 3, 1998.

TECHNICAL FIELD

This invention relates to a structure of a thermoelectric device and amethod of fabricating the thermoelectric device, and more particularly,a structure of a pad for a lead line to connect a thermoelectric deviceto another circuit, and a method of fabrication thereof.

BACKGROUND TECHNOLOGY

Various metal materials have been used for electric parts, andmicronization of the electric parts is being developed every year. Atypical example is a thermoelectric device. In the thermoelectricdevice, a voltage is generated by providing a difference in temperaturebetween the opposite ends thereof. A device designed to extract thevoltage as electric energy is a thermoelectric power generator. Such athermoelectric device wherein heat energy can be converted directly intoelectric energy has attracted much attention as an effective means ofutilizing heat energy, as represented by the case of waste heatutilization.

Meanwhile, the flow of a current caused to occur through thethermoelectric device results in generation of heat at one end thereof,and absorption of heat at the other end thereof. This is due to thePeltier effect, and a cooler can be manufactured by taking advantage ofsuch a phenomenon of heat absorption. This type of cooler which does notcomprise mechanical components and can be reduced in size has anapplication as a portable refrigerator, or a localized cooler forlasers, integrated circuits, and the like.

The thermoelectric device which is applicated the thermoelectric powergenerator or cooler is simple in construction, and is in a morefavorable condition for miniaturization as compared with other types ofpower generators, and there will not arise a problem of leakage ordepletion of electrolyte as with the case of a redox cell. Therefore,the thermoelectric device has promising prospects for application toportable electronic devices such as an electronic wrist watch.

The thermoelectric device is formed with plural thermocouples consistingof p-type and n-type thermoelectric semiconductors, aligned in series.

In the case of the difference in temperature between a cold junction anda hot junction of the thermoelectric device is 1.30° C., in order toobtain voltage of more than 1.5 V which is necessary for driving thewrist watch, more than 2000 pairs of thermocouples are required evenwith a BiTe-based thermocouples which is said to have a high performanceindex.

The thermoelectric device is required to be as small in size aspossible, because it is disposed in a highly-limited space such as theinterior of a wrist watch. Therefore, a highly-dense and minutethermoelectric device in size is required so that many thermocouples canbe arranged in a limited area.

For example, Japanese Patent Laid-open No. 63-20880 discloses a methodof fabrication of a miniaturized thermoelectric device with plenty ofthermocouples in high density.

In this publication, mentioned is a method of fabrication to form ap-type bar-shaped device and an n-type bar-shaped devices in a mannersuch that the p-type and n-type thermoelectric materials in a thinsheet-like shape are laminated on top of each other in layers whileinterposing a heat insulating material between respective p-type andn-type thermoelectric material layers, and grooves are formed at fixedintervals in a perpendicular s direction to a laminated surface. Thep-type bar-shaped device and the n-type bar-shaped device are connectedin series with electrode materials at each end.

The thermoelectric device formed with the above-described method has asize of 30×20×3.5 (mm), containing 3500 pairs of thermocouples, whichamounts to 7000 pieces of the total of the bar-shaped devices in anextremely high density.

However, in the case of connecting to another circuit from thisthermoelectric device, current must be taken out from one of theelectric patterns shown here. When ordinary solder is used to take outthe lead line for this purpose, it needs very fine work and a specialdevice. In addition, formation of a large electrode for the lead linerequires a large thermoelectric device itself, which is inconvenient todispose in a limited space.

It is an object of the present invention to solve the above-describeddisadvantages and to provide a structure of the thermoelectric devicewhich takes out a lead line easily and efficiently while having a fineand high-density structure, and a method of fabrication thereof.

DISCLOSURE OF THE INVENTION

In order to achieve the above described objects, the present inventionadopts a structure explained hereinafter in the thermoelectric deviceand the method of fabrication thereof.

The thermoelectric device of the present invention comprises athermoelectric device block having two interconnecting end faces onwhich a plurality of n-type bar-shaped devices consisting of n-typethermoelectric semiconductors and a plurality of p-type thermoelectricdevices consisting of p-type thermoelectric semiconductors are regularlydisposed through an insulating layer and fixed, and both end faces ofeach of said n-type bar-shaped devices and p-type bar-shaped devices areexposed, an interconnection conductor connecting each end face of saidn-type bar-shaped device and p-type bar-shaped device on said eachinterconnecting end face of said thermoelectric device block to connectsaid n-type bar-shaped devices and p-type bar-shaped devices in series,a pair of terminal conductors provided on a surface excluding saidinterconnecting end face of said thermoelectric device block, andelectrically connected each bar-shaped device at least on one endportion and the other end portion of the n-type bar-shaped device andp-type bar-shaped device connected in series.

At this time, the bar-shaped devices at least on one end portion and theother end portion of the n-type and p-type bar-shaped devices connectedin series may be exposed on one surface excluding the interconnectingend face of the above described thermoelectric device block, andrespective one and the other of said pair of terminal conductors are maybe made contact with and provided on the exposed surface of eachbar-shaped device.

Alternatively, each bar-shaped device on the above-described one endportion and the other end portion can be exposed to one surface and theother surface of opposing two surfaces excluding the interconnecting endfaces, and one and the other of the above-described pair of terminalconductors can be provided in contact with the exposed surfaces of theabove described one surface and the other surface of each bar-shapeddevice to form the thermoelectric device.

Furthermore, it is also acceptable to make a thermoelectric device in amanner such that each bar-shaped device provided on at least one endportion and the other end portion of the n-type and p-type bar-shapeddevices connected in series is exposed respectively to the chamferedoblique surface formed between one surface excluding the interconnectingend surface and the adjacent surface, and one and the other terminalconductors are respectively provided in contact with the exposed surfaceof the chamfered oblique surface and the exposed surface of the otherchamfered oblique surface of each above-described bar-shaped device.

Alternatively, it is also possible to make a thermoelectric device in amanner such that the above-described thermoelectric device block has aplurality of device lines in which the n-type bar-shaped devices and thep-type bar-shaped devices align alternately, and consists of a firstinterconnection conductor connecting each end face of adjacent n-typeand p-type bar-shaped devices, which are contained in the same deviceline among the plural device lines in a parallel direction to the deviceline, a second interconnection conductor connecting each end face ofn-type and p-type bar-shaped devices spreading across the adjacentdevice line, and a pair of third interconnection conductor connected toeach end face of each bar-shaped device provided at least on one endportion and the other portion of n-type and p-type bar-shaped devicesconnected in series with the first and second interconnectionconductors, and a pair of the terminal conductors connect to the thirdinterconnection conductors respectively.

Furthermore, a thermoelectric device can be structured in a manner suchthat while a plurality of the similar device line to that describedabove are provided, the thermoelectric device is provided with similarfirst and second interconnection conductors to those described above,and a pair of third interconnection conductors connected to each endface of the first bar-shaped device group containing the bar-shapeddevices at least on one end portion of the n-type and p-type bar-shapeddevices connected in series with the first and second interconnectionconductors and each end face of the second bar-shaped device groupcontaining the bar-shaped devices on the other end portion thereofrespectively, and the bar-shaped device of the first bar-shaped devicegroup and the bar-shaped device of the second bar-shaped device groupare exposed on a surface excluding the above-described interconnectingend face of the above-described thermoelectric device block, and a pairof the terminal conductors connect to an exposed surfaces of thebar-shaped devices of the above described respective groups.

In this thermoelectric device, each bar-shaped device provided on oneend portion and the other end portion of the n-type and p-typebar-shaped devices connected in series may be located near the diagonalposition in relation to the interconnecting end face of thethermoelectric device block.

Furthermore, these thermoelectric devices can be structured in a mannersuch that a pair of terminal conductors are formed on one surface exceptthe interconnecting end face of the thermoelectric device block, orformed one each on the opposing two surfaces excluding theinterconnecting end face of the thermoelectric device block.

In addition to the above, the present invention characterized in themethod of fabrication of the thermoelectric device which includes a stepof forming a block of the thermoelectric devices, a step of forming aplurality of thermocouples by connecting each end face of n-type andp-type bar-shaped devices on the interconnecting end face with aninterconnection conductor in a manner such that a plurality of n-typeand p-type bar-shaped devices are connected in series alternately, and astep of forming a pair of terminal conductors electrically connectedrespectively with bar-shaped devices provided at least on one endportion and the other end portion of plural thermocouples connected inseries on a surface excluding the interconnecting end faces.

In this method of fabrication, a terminal conductor may be formed on onesurface excluding the interconnecting end face, or on two surfacesopposite to each other.

Alternatively, the method may have a step of exposing on a surfaceexcluding the interconnecting end surface, each bar-shaped deviceprovided at least on one end portion and the other end portion of theplural thermocouples connected in series before forming the terminalconductor, to form by bringing one and the other of a pair of theterminal conductors to contact with one and the other exposed surface ofeach bar-shaped device.

In this case, the formation can be carried out by exposing eachbar-shaped device on two opposite surfaces excluding the interconnectingend face, and by contacting one and the other of a pair of terminalconductors with each one and the other exposed surface of eachbar-shaped device.

The thermoelectric device can be structured with a step of forming eachchamfered oblique surface by cutting or grinding corner portions formedwith a surface excluding the interconnecting end face and each surfaceadjacent to both ends of the surface thereof and exposing bar-shapeddevices provided at least on one end and the other end of pluralthermocouples connected in series on one and the other chamfered obliquesurfaces, and a step of respectively contacting one and the other of apair of terminal conductors with each bar-shaped device on the exposedsurfaces of chamfered oblique surfaces.

In each above-described method of fabrication, steps of forming thethermoelectric device block can include a step of forming a longitudinalgroove and a longitudinal partition wall on an n-type thermoelectricsemiconductor block and a p-type thermoelectric semiconductor block tomake an n-type grooved block and a p-type grooved block, a step offorming an integrated block by combining the longitudinal groove and thelongitudinal partition wall inserted into each other to unite the n-typegrooved block and the p-type grooved block, and by forming a insulatingadhesive layer in a space between the inserting portions of both blocks,a step of making an integrated grooved wall block with by forming atransverse groove and a transverse partition in a direction intersectingwith the above-described transverse groove on the integrated block, astep of forming a block by forming an insulating layer on the transversegroove of the integrated grooved wall block so that a block can beformed on which the plural n-type bar-shaped devices and the pluralp-type bar-shaped devices are regularly arranged through the insulatinglayer, and a step of forming two interconnecting end faces by cutting orgrinding two surfaces intersecting with the longitudinal direction ofthe n-type bar-shaped device and the p-type bar-shaped device of theblock to expose both end faces of aforementioned each n-type bar-shapeddevice and each p-type bar-shaped device.

In the present invention, a lead line is pulled out from a surfaceexcluding the interconnecting end surfaces which connects each end faceof the bar-shaped devices in the thermoelectric device. Accordingly, nospace is required for providing a lead line, which gives thethermoelectric device better space efficiency. It is effective for asmall size thermoelectric device.

Even in the case of a highly dense device, a space for a lead line canbe provided with a certain measure of width irrespective of the fineinterconnection electrode pattern. Therefore workability is good and areliable electric contact is given.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing an example of an n-type and p-typethermoelectric semiconductor blocks of the present invention;

FIG. 2 is a perspective view showing an example of n-type and p-typegrooved blocks;

FIG. 3 is a perspective view showing an integrated state, combining then-type and p-type grooved blocks in FIG. 2;

FIG. 4 is a perspective view showing an integrated grooved block inwhich a transverse groove is formed on the integrated block in FIG. 3;

FIG. 5 is a perspective view showing a state in which an insulatingresin layer is formed on the integrated grooved block in FIG. 4;

FIG. 6 is a perspective view showing a thermoelectric device block whichis obtained by grinding a side face of the integrated grooved block inFIG. 5;

FIG. 7 is a plane view of the thermoelectric block;

FIG. 8 is a plane view of a thermoelectric device on which aninterconnection pattern is formed;

FIG. 9 is a perspective view of the same;

FIG. 10 is a back view of the same;

FIG. 11 is a perspective view of a thermoelectric device block on whichanother interconnection pattern is formed;

FIG. 12 is a partly omitted cross sectional view of an example of athermoelectric device block in a manufacturing process of athermoelectric device;

FIG. 13 is a partly omitted cross sectional view of another examplethereof;

FIG. 14 is a partly omitted cross sectional view of still anotherexample of thereof;

FIG. 15 is a partly omitted cross sectional view of yet another exampleof thereof;

FIG. 16 is a perspective view showing a modified example of thethermoelectric device block;

FIG. 17 is a perspective view showing another modified example of thethermoelectric device block on which an interconnection pattern isformed;

FIG. 18 is a perspective view showing still another modified example ofthe thermoelectric device;

FIG. 19 is a perspective view showing a state in which aninterconnection pattern is formed on the thermoelectric device block inFIG. 18;

FIG. 20 is a perspective view showing yet another modified example ofthe thermoelectric device block;

FIG. 21 is a perspective view showing a state in which aninterconnection pattern is formed on the thermoelectric device block inFIG. 20; and

FIG. 22 to FIG. 25 are plane views showing modified examples ofinterconnection patterns of the thermoelectric device.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a structure of a thermoelectric device and a method offabrication of the same will be explained with reference to thedrawings. First embodiment of the structure of thermoelectric device:FIG. 8 to FIG. 10

First, the structure of the thermoelectric device according to thepresent invention will be explained.

As shown in FIG. 9, the thermoelectric device of the present inventionis structured mainly with a thermoelectric device block 53 and aconductor 58 formed on the surface thereof.

The thermoelectric device block 53 is structured as shown in the drawingin a manner such that an n-type bar-shaped device 51 in which an n-typethermoelectric semiconductor is processed into a square column and ap-type bar-shaped device 52 in which a p-type thermoelectricsemiconductor is similarly processed, are arranged regularly and fixedto integrate with each other into a cuboid like shape.

The thermoelectric device block 53 contains an insulating layer 50 madeof an insulating resin to insulate the n-type bar-shaped device 51 andthe p-type bar-shaped devices 52, among each of the n-type bar-shapeddevices 51, and among each of the p-type bar-shaped devices 52respectively, and to fix the n-type bar-shaped device 51 and the p-typebar-shaped device 52.

The thermoelectric device block 53 has an upper surface 53 a and a lowersurface 53 b as two interconnecting end faces which are made by exposingboth end faces of the n-type bar-shaped device 51 and the p-typebar-shaped device 52, and has one of a surface excluding theinterconnecting end faces as a side surface 53 c.

A conductors 58 consists of plural interconnection conductors 58 a toconnect respective end faces of the n-type bar-shaped device 51 and thep-type bar-shaped device 52 on the upper surface 53 a and the lowersurface 53 b, and terminal conductors 58 b provided on the side surface53 c.

The interconnection conductor 58 a is structured on the upper surface 53a and the lower surface 53 b in an arrangement shown in FIG. 8 and FIG.10. Each end face of the n-type bar-shaped device 51 and the p-typebar-shaped device 52 is connected with the interconnection conductor 58a to form a series of thermocouples in which a plurality of n-typebar-shaped devices 51 is and p-type bar-shaped devices 52 are connectedrespectively in series so that the thermocouples can be formed as manyas possible.

The terminal conductors 58 b are formed in a pair on a side surface 53 cof the thermoelectric device block 53, as shown in FIG. 9, and eachterminal conductor 58 b is electrically connected to the bar-shapeddevices containing each of bar-shaped devices 51 a, 52 a provided on oneend portion and the other end portion of a series of the n-type andp-type bar-shaped devices connected in series. Each terminal conductor58 b is also electrically connected to the interconnection conductors 58a. The terminal conductor 58 b serves as a pad for a lead line, to whichanother lead wire can be connected with solder or a conductive adhesiveagent. The lead wire is used for connecting to another devices orcircuits. First embodiment of a method of fabricating the thermoelectricdevice: FIG. 1 to FIG. 10

Next, a method of fabricating the thermoelectric device of the presentinvention will be explained.

First, as shown in FIG. 1, an n-type thermoelectric semiconductor block1 and a p-type thermoelectric semiconductor block 2 are prepared. Then-type thermoelectric block 1 and the p-type thermoelectricsemiconductor block 2 are semiconductor blocks which will besquare-column-shaped n-type and p-type bar-shaped devices respectivelyafter processing, and it is preferable to be the same in all the sizesincluding length. Incidentally, in the drawings, diagonal are providedto the n-type thermoelectric semiconductor block 1 to make both blockseasily distinguishable.

In this embodiment, an n-type BiTe sintered body, that is an n-typethermoelectric semiconductor, is used for the n-type thermoelectricsemiconductor block 1 and a p-type BiTeSb sintered body, that is ap-type thermoelectric semiconductor, is used for the p-typethermoelectric semiconductor block 2, the dimensions of the both blocksbeing set at 12 mm ×12 mm×4 mm.

Then, as shown in FIG. 2, a plural number of longitudinal grooves 26 areformed in parallel at fixed pitches on the n-type thermoelectricsemiconductor block 1, and a longitudinal partition wall 27 is formed atthe same time to form a comb-tooth n-type grooved block 21. Similarly, ap-type grooved block 22 is formed from the p-type thermoelectricsemiconductor block 2. At this time, the longitudinal grooves 26 of then-type grooved block 21 and the p-type grooved block 22 are made thesame in pitch, and the width of the longitudinal groove 26 on one blockis made larger than the width of the other longitudinal partition wall27.

The width of the longitudinal groove 26 is set in a suitable value, indue consideration of fixing the n-type grooved block 21 and the p-typegrooved block 22 with each other in the following process. Thedifference in width between the longitudinal groove 26 and thelongitudinal partition wall 27 corresponds to the width of a portionwhich will later serve as an insulating resin layer. Consideringreliable insulation between the n-type grooved block 21 and the p-typegrooved block 22, and the working efficiency in the fixing process ofboth blocks, which will be mentioned later, the difference is preferablymore than 10 μm.

Incidentally, the processing of the longitudinal groove 26 can becarried out by polishing with a wire saw.

The cross section of the wire of the wire saw is round, so strictlyspeaking, the shape of the bottom of the processed groove of thelongitudinal groove 26 is a curved surface, but for the convenience ofdrawing, it is displayed in a form of a flat bottom in FIG. 2.

A longitudinal groove 26 having 3 mm in depth (the length 4 mm of theexternal shape is taken as a thickness direction), 120 μm in pitch, and70 μm in width is formed using the wire saw.

Next, as shown in FIG. 3, the n-type grooved block 21 and the p-typegrooved block 22 shown in FIG. 2 are integrated by combining and fixingthe longitudinal grooves 26 and the longitudinal partition walls 27 witheach other. The combined two blocks are fixed with an insulatingadhesive layer 62, having an insulating quality, provided in the spaceof each engaging portion to obtain an integrated block 3.

A point to be careful in an adhering process to prepare the integratedblock 3 is that the adhesive layer 62 must have a function not only toadhere the two blocks but also to ensure an electrically insulatingproperty between the n-type grooved block 21 and the p-type groovedblock 22.

When the inside wall of the longitudinal groove 26 can be processed toobtain an extremely smooth surface by the polishing process with thewire saw, the integrated block 3 before bonding is partially immersed inan adhesive agent having high fluidity (for instance, low-viscosity,normal temperature thermosetting type epoxy-based adhesive), and theadhesive agent is allowed to fill in the space between the longitudinalgrooves 26 and the longitudinal partition walls 27 through a capillaryphenomenon, thereby the electrical insulating property on the adhesivelayer 62 can be ensured.

Now, thus completed integrated block 3 in FIG. 3 is provided with aplurality of transverse grooves 46 (4 grooves in the drawing) atpredetermined pitches, which are formed by another groove making processshown in FIG. 4 to complete an integrated grooved block 43.

The processing of the transverse groove 46 can be performed in a similarmanner to the processing of the longitudinal grooves 26 in FIG. 2through the polishing process with a wire saw. Then, transversepartition walls 47 are formed at predetermined intervals on a residualportion. Incidentally, the transverse grooves 46 may be formed in thedirection intersecting with the longitudinal groove 26, but in generalit is most suitable to form the transverse grooves 46 to intersect withthe longitudinal groove 26 at right angles as shown in FIG. 4.

The transverse grooves 46 can be formed from any surface on the p-typethermoelectric semiconductor side, or, on the contrary, on the n-typethermoelectric semiconductor side. That is, the transverse grooves 46can be formed from any of upper or lower side of the integrated block 3.The transverse groove 46 is preferably formed in a depth to the rootportion of the longitudinal grooves 26 or the longitudinal partitionwalls 27 of the n-type thermoelectric semiconductor and the p-typethermoelectric semiconductor of the integrated block 3.

The width of the transverse groove 46 is, unlike the longitudinal groove26, preferably to be as fine as possible. This is because, as understoodfrom the next process, the portion to contribute to the power generationcapacity is a portion of the transverse partition walls 47 and it ispreferable to make the area of the transverse groove 46 as small aspossible from the point in quality of the thermal electric device.

Accordingly, in this embodiment, a transverse groove 46 of 120 μm inpitch length, 40 μm in width, and 3 mm in depth is formed.

Incidentally, the value 40 μm of the transverse width is nearly thenarrowest value as the width obtained by the wire saw processing.

Next to the process in FIG. 4, as shown in FIG. 5, an insulating resinlayer 54 is formed by filling an epoxy-based insulating resin in thetransverse groove 46 and curing thereof. That is, a mold (not shown)which houses the integrated grooved block 43 is prepared, and after theintegrated grooved block 43 is housed in the mold, an insulating resinis filled in the mold. Then, the mold is removed. Then, the upper andlower surfaces of the integrated grooved block 43 covered with theinsulating resin layer 54 are removed by grinding or polishing. Thus thefinishing process to expose the engaging portion of the transversegrooves 26 with the longitudinal partition walls 27 (the root portion ofthe longitudinal partition walls 27) of the n-type thermoelectricsemiconductor and the p-type thermoelectric semiconductor is carriedout, and a thermoelectric device block 53 shown in FIG. 6 is formed.

Since the aforementioned adhesive layer 62 shown in FIG. 3 and theinsulating resin layer 54 shown in FIG. 5 are layers which have the samefunction of obtaining electric insulation, both are put together into aninsulating layer 50 in and after FIG. 6.

A plane view of the thermoelectric device block 53 in this state, whichis seen from right above, is shown in FIG. 7. It is noted that thethermoelectric device block 53 in this state has a figure that eachthree lines are regularly aligned alternately, in which a line has a setof five pieces, seen from right above, of each n-type bar-shaped devices51 and p-type bar-shaped devices 52. Both of the horizontal crosssection of the n-type bar-shaped device 51 and the p-type bar-shapeddevices 52 are rectangles, each having 50 μm×80 μm in size. Thus, when athermoelectric device block 53 is 6 mm×2.4 mm×2 mm in dimension, theblock 53 contains each 1000 pieces of the n-type bar-shaped device 51and the p-type bar-shaped devices 52 having 50 μm×80 μm×2000 μm in size,that is, 1000 pairs of the thermocouples.

Next, each end face of the n-type bar-shaped device 51 and the p-typebar-shaped device 52 is electrically connected to each other with aconnection conductor 58 a on the upper surface 53 a and the lowersurface 53 b of the thermoelectric device block 53 shown in FIG. 6. Thisis carried out in a manner such that metallic masking films, made ofnickel, having apertures corresponding to each interconnection patternon the upper surface 53 a and the lower surface 53 b are placed in theposition in relation to each of the upper surface 53 a and the lowersurface 53 b, and fixed in intimate contact, and then a formation ofmetal film by vapor deposition is carried out.

Then, a pair of terminal conductors 58 b which serve as a pad forconnecting a lead line for other circuits is formed on one side surface53 c of the thermoelectric device block 53. This is formed in a mannersuch that metallic masking films having an aperture corresponding to theterminal conductor 58 b is placed on the side surface 53 c and fixedintimately and a metal vapor oblique deposition process is carried out.The thickness of the vapor deposition film is 100 nm by chromium and 900nm by copper.

As described above, an interconnection pattern of the interconnectionconductor 58 a shown in FIG. 8 to connect the n-type bar-shaped device51 and the p-type bar-shaped devices 52 is formed on the upper surface53 a of the thermoelectric device 53, and a pair of the terminalconductors 58 b shown in FIG. 9 are formed on the side surface 53 c.Incidentally, since each terminal conductor 58 b and the interconnectionconductor 58 a are formed simultaneously by the vapor deposition, theyare connected to each other.

Next, an interconnection process to connect each end face of the n-typebar-shaped device 51 and the p-type bar-shaped devices 52 is carried outon the lower surface 53 b of the thermoelectric device block 53 shown inFIG. 6.

That is, a metallic masking film having an aperture corresponding to theinterconnection pattern on the lower surface 53 b is fixedly positionedat a predetermined position on the lower surface 53 b, and a film havingthe thickness of 100 nm by chromium, 900 nm by copper is formed bysimilar vapor deposition process as described above. Thus, theinterconnection pattern shown in FIG. 10 is formed on the lower surface53 b with the interconnection conductor 58 a.

As described above, when end faces of each n-type bar-shaped device andp-type bar-shaped device are connected with the interconnectionconductor 58 a, the process is carried out to obtain a plurality ofthermocouples which are formed such that the n-type and p-typebar-shaped devices 51, 52 are connected alternately in series. Theterminal conductor 58 b as well as the interconnection conductor 58 acan be electrically connected to each of bar-shaped devices 51 a, 52 awhich are provided on one end portion and the other end portion ofplural thermocouples formed here, and lead wires (not shown) can besoldered to each terminal conductor 58 b. The lead wire can be used as alead line for other circuits or other thermoelectric devices.

Through the above interconnection process, 1000 pairs of thermocouplesconsisting of the n-type bar-shaped device 51 and the p-type bar-shapeddevices 52 are electrically connected in series. Since each terminalconductor 58 b is electrically connected to each bar-shaped electricdevices 51 a, 52 a which are provided on one end portion and the otherend portion of a series of the thermocouples connected in series,voltage generated by 1000 pairs of the thermocouples can be taken outefficiently by connecting the lead lines to each terminal conductor 58b.

In this case, since no interconnection pattern is provided on the sidesurface 53 c on which the terminal conductor 58 b is formed, asufficient space can be ensured, and additionally, only two points arerequired for the terminal conductor 58 b as a pad for a lead line on thespace of the side surface 53 c. Accordingly, since the terminalconductor 58 b is not required to be in an extremely fine structure butcan be formed in some extent of size, the lead line can be easilyconnected with solder or a conductive adhesive agent.

The electric resistance value of the thermoelectric device containing1000 pairs of thermocouples prepared by this manufacturing process is 11kΩ, which is only 10 % higher compared with the theoretical electricresistance value of the material only.

The electromotive force is 392 mV/° C., showing the value of 98% inrelation to the same theoretical characteristic, which is sufficiently apractical level.

The size of the thermoelectric device thus prepared is 6 mm×2.4 mm×2 mm.Since the number of thermocouples required to drive a wrist watch with atemperature difference of 1.3° C., and to obtain voltage of 2.6 Vsufficient for charging is 5000 pairs, it is necessary to house fivepieces of the thermoelectric devices thus prepared. However, since thecross sectional area of the total five pieces of the thermoelectricdevices is only 72 mm², it can be made sufficiently small to house themin the interior of the wrist watch.

Second embodiment of the method of fabricating the thermoelectricdevice: FIG. 1 to FIG. 10, and FIG. 12 to FIG. 15

Next, the second embodiment of the method of fabricating thethermoelectric device will be explained. The second embodiment of themethod of fabrication can produce the similar thermoelectric device tothat in the first embodiment of the manufacturing method, butapplication of a photolithography technology and an etching technologyis a different aspect from the first embodiment of the manufacturingmethod.

First, a thermoelectric device block 53 is formed using a similar methodto that explained in the first embodiment of the manufacturing methodwith reference to FIG. 1 to FIG. 6.

A plane view of the thermoelectric device block 53 seen from right aboveis shown in FIG. 7.

The thermoelectric device block 53 is the same in the state of alignmentof the n-type bar-shaped device 51 and the p-type bar-shaped device 52,size, and shape as those in the first embodiment of the manufacturingmethod.

Next, interconnection of the n-type bar-shaped device 51 and the p-typebar-shaped device 52 on the upper surface 53 a and the lower surface 53b of the thermoelectric device block 53 and connection of a lead line onthe side surface 53 c are carried out as the following explanation.

A metallic film 14 made of titanium by spattering and having 1 μm inthickness is formed simultaneously on the upper surface 53 a, the lowersurface 53 b and on the side surface 53 c. A cross sectional view of thethermoelectric device block 53 seen from the lateral direction is shownin FIG. 12.

As shown in FIG. 12, a photosensitive resin film 16 made of apositive-type fluid resist is formed on the metallic film 14. In thiscase, a photolithography technology consisting of an exposure process toirradiate light onto the photosensitive resin film 16 with a photomaskand a development process to dissolve and remove the exposed portion, isperformed, thereby the photosensitive resin film 16 is formed only on aportion where the n-type bar-shaped device 51 and the p-type bar-shapeddevice 52 are connected, as shown in FIG. 13.

At this time, an interconnection pattern on the upper surface 53 a ismade similar to the interconnection pattern shown in FIG. 8, and in thecase of the lower surface 53 b, it is made similar to that in FIG. 10,and in the case of the side surface 53 c, similar to that in FIG. 9.

Then, the thermoelectric device block 53 is immersed in 0.5 %hydrofluoric acid aqueous solution to solve and remove a metallic film14 made of titanium on a non-electrode portion which is an opened areaof the photosensitive resin film 16, which results in a state shown in across sectional view of FIG. 14.

Then, the photosensitive resin film 16 consisting of a positive-typefluid resist is, as shown in FIG. 15, immersed in a resist stripper tosolve and remove the resin film 16. Through this process, theinterconnection pattern of the metallic film 14 consisting of titaniumbecomes the same pattern as shown in FIG. 8 for the upper surface 53 a,the same pattern as shown in FIG. 10 for the lower surface 53 b, and thesame pattern as shown in FIG. 9 for the side surface 53 c.

It should be noted that the figure in which the interconnection patternsin FIG. 8 and FIG. 10 are prepared by connecting the n-type bar-shapeddevice 51 and the p-type bar-shaped device 52 alternately in series toform a series of plural thermocouples is the same as that in the firstembodiment of the manufacturing method.

It is also the same aspect as those in the first manufacturing methodthat the terminal conductor 58 b shown in FIG. 9 as well as theinterconnection conductor 58 a is electrically connected with eachbar-shaped devices 51 a, 52 a provided on one end portion and the otherend portion of the thermocouples connected in series, and the number ofthe thermocouples is preferably as many as possible.

The terminal conductor 58 b is the same as in the first embodiment ofthe manufacturing method in that it can connect a lead wire bysoldering, and the lead wire can be used as a lead line for othercircuits or other thermoelectric devices. Furthermore, the point thatvoltage generated by a series of the thermocouples can be taken out byconnecting a lead line to the terminal conductor 58 b is the same asthat in the first embodiment of the manufacturing method, and the pointthat the connection of the lead line can be easily performed is thesame.

The electric resistance value and the electric motive force of thethermoelectric device containing 1000 pairs of the thermocouplesprepared by this manufacturing method are nearly the same as those ofthe thermoelectric device prepared in the first embodiment of themanufacturing method explained before. Since the size and shape are alsothe same, the cross sectional area required for 5000 pairs of thethermocouples is the same as in the first embodiment of themanufacturing method.

Second Embodiment of the Structure: FIG. 8, FIG. 10 and FIG. 11

Next, the second embodiment of the structure of the thermoelectricdevice will be explained.

A thermoelectric device in this embodiment is different from thethermoelectric device in the first embodiment in that, as shown in FIG.11, terminal conductors 58 b are formed on each one portion of opposingtwo side surfaces 53 d, 53 e which exclude the interconnection terminalsurfaces. Since other points are the same as those in the firstembodiment, the explanation thereof will be omitted.

Each one of the terminal conductors 58 b in the present embodiment isformed on the opposing two side surfaces 53 d, 53 e of thethermoelectric device block 53, and each terminal conductor 58 b as wellas the interconnection conductor 58 a is electrically connected to eachbar-shaped devices 51 a, 52 a corresponding to one end portion and theother end portion of the bar-shaped device consisting of the n-type andp-type bar-shaped devices 51, 52 connected in series. The terminalconductor 58 b serves as a pad for a lead line, and can connect to alead wire (not shown) with solder or a conductive adhesive agent, andthe lead wire can be used to connect to another device or anothercircuit, which is the same as that in the first embodiment.

In the thermoelectric device block 53 according to the presentembodiment, in order to form the terminal conductors 58 b on the twoopposing side surfaces 53 d, 53 e, the vapor deposition is necessary toperform twice, but it is desirable because the wiring between each blockis made easier, compared with the thermoelectric device block 53 in thefirst embodiment when plural blocks are connected in series.

Third Embodiment of the Method of Fabricating the Thermoelectric Device:FIG. 1 to FIG. 8, FIG. 10, and FIG. 11

Next, the third embodiment of the method of fabricating thethermoelectric device will be explained.

The present embodiment is different from the first embodiment of themanufacturing method in the respect that a forming process of a terminalconductors 58 b is to form one each of the terminal conductors 58 b ontwo opposing side surfaces 53 d, 53 e, and since other processes are thesame as those in the first embodiment of the manufacturing method, theexplanation thereof will be omitted.

First, a thermoelectric device block 53 is formed in a similar manner tothat in the first embodiment of the manufacturing method, and at thesame time interconnection of the n-type and p-type bar-shaped device 51,52 on the upper surface 53 a and the lower surface 53 b with theinterconnection conductor 58 a is carried out. Then terminal conductors58 b which will be a connecting pad for a lead line to other circuits isformed respectively on side surfaces 53 d, 53 e. The formation of theterminal conductors 58 b is performed using a metallic masking filmhaving an aperture corresponding to the terminal conductor 58 b. Thatis, the metal masking films are arranged on each position of the sidesurfaces 53 d, 53 e so as to electrically connect to bar-shaped devices51 a, 52 a on one end portion and the other end portion of the n-typeand p-type bar-shaped devices 51, 52 connected in series, and areintimately fixed. Then, the formation is completed by conducting vapordeposition while the thermoelectric device block 53 is rotated. The filmthickness of the vapor deposition is 100 nm by chromium and 900 nm bycopper.

While an interconnection pattern is formed on the upper surface 53 a andthe lower surface 53 b with an interconnection conductor 58 a as shownin FIG. 8 and FIG. 10, one each of the terminal conductors 58 b whichwill be a pad for a lead line as shown in FIG. 11 is formed on the sidesurface 53 d, 53 e by the vapor deposition. At this time, theinterconnection conductor 58 a on the upper surface 53 a and theterminal conductors 58 b on the side surfaces 53 d, 53 e aresimultaneously formed by the vapor deposition to connect with each otheras shown in FIG. 11.

The relation between the interconnection patterns in FIG. 8 and FIG. 10is the same as that in the first embodiment in such that the n-typebar-shaped devices 51 and the p-type bar-shaped devices are alternatelyconnected in series to form a plurality of thermocouples. It is also thesame as in the first embodiment that the interconnection conductor 58 aand the terminal conductors 58 b are electrically connected respectivelyto the bar-shaped devices 51 a, 52 a on one end portion and the otherend portion of plural thermocouples connected in series so that as manyas thermocouples can be obtained. In addition, the aspect in which leadwires are connected to the terminal conductors on the side surfaces 53d, 53 e by soldering and the lead wire is used for a lead line to othercircuits and other thermoelectric power generating devices is the sameas in the first embodiment. Thus, since no interconnection pattern isrequired on the side surfaces 53 d, 53 e, a sufficient space is secured,and since only one each of the pads for the lead line is required oneach space having a surface area of 2.4 mm×2 mm which is the dimensionof the side surfaces 53 d, 53 e, the pads can be formed with some extentof dimension. Therefore, the connection of the lead wire can be easilycarried out, which is also the same as that in the first embodiment.

Incidentally, the electric resistance value and the electromotive forceof the thermoelectric device containing 1000 pairs of thermocouplesprepared by the above described manufacturing method are nearly the sameas those prepared by the first embodiment of the manufacturing method.And since the dimension and the shape are also the same, total of fivecross sectional areas necessary for 5000 pairs of the thermocouples isthe same as the area in the first embodiment of the manufacturingmethod.

Third Embodiment of the Structure: FIG. 8, FIG. 10, and FIG. 17

Next, the third embodiment of the structure will be explained. Thethermoelectric device in the present embodiment differs from thethermoelectric device in the first embodiment in that, as shown in FIG.17, each one portion of the n-type and p-type bar-shaped devices 51 a,52 a at least on one end portion and the other end portion of the n-typeand p-type bar-shaped devices 51, 52 connected in series is exposed fromone side surface of the thermoelectric device block 53 so as to make theterminal conductor 58 b contact with the n-type bar-shaped device 51 aor the p-type bar-shaped device 52 a so that a pair of terminalconductor 58 b can be formed.

The interconnection conductors 58 a are arranged in a manner as shown inFIG. 8 for the upper surface 53 a and in FIG. 10 for the lower surface53 b, and in order to obtain the thermocouples as many as possible,terminal conductor 58 b is electrically connected respectively to thebar-shaped devices 51 a, 52 a corresponding to one end portion and theother end portion of the n-type and p-type bar-shaped devices 51, 52connected in series, which is, of course, the same as that in the firstembodiment.

Incidentally, what is in the drawing has a structure in which eachterminal conductor 58 b is not connected to the interconnectionconductor 58 a, but both conductors may connect with each other whilechanging the position for the formation.

Fourth Embodiment of the Method of Fabricating the ThermoelectricDevice: FIG. 1 to FIG. 8, FIG. 10, FIG. 16, and FIG. 17

Next, the fourth embodiment of the method of fabricating thethermoelectric device will be explained. The present embodiment differsfrom the first embodiment of the manufacturing method in that, beforethe formation of a terminal conductor 58 b, a portion of the n-type andp-type bar-shaped devices 51, 52 connected in series is exposed from aside surface 31 so that a process to form a terminal conductor 58 b onthe exposed surface is provided.

In this process, a side surface 53 c of the thermoelectric device block53 formed in the same manner as that in the first embodiment is groundor polished to expose, as shown in FIG. 16, each bar-shaped device so asto include each of the bar-shaped devices 51 a, 52 a on one end portionand the other end portion of plural thermocouples consisting of then-type and p-type bar-shaped devices 51, 52 connected in series, tothereby form the side surface 31. In addition, the process can beperformed at the time when the upper surface and the lower surface ofthe thermoelectric device block 53 are ground or polished in the firstembodiment of the manufacturing method to be performed simultaneouslywith the formation of the thermoelectric device block 53.

Then, each end face of the n-type bar-shaped devices 51 and the p-typebar-shaped devices 52 is electrically connected to form theinterconnection pattern as shown in FIG. 8 and FIG. 10 on the uppersurface 53 a and on the lower surface 53 b in the same manner as that inthe first embodiment of the manufacturing method, and a pair of theterminal conductors 58 b are formed so as to contact across the n-typeand p-type bar-shaped devices 51 a, 52 a on one end portion and theother end portion on the side surface 31. This is performed by making ametal film having an aperture corresponding to the terminal conductors58 b as shown in FIG. 17 an intimate contact with the side surface 31and fixing with each other and by forming a vapor deposition film asdescribed above.

In the present embodiment, the vapor deposition film is formed as a padfor a lead line, but the n-type bar-shaped devices 51 and the p-typebar-shaped devices 52 exposed on the side surface 31 can be directlysoldered without forming the vapor deposition film. However, since thebar-shaped device is made of BiTeSb-based material, solder is alsorequired to be of the same sort of material. Therefore, it is desirableto carry out the vapor deposition to form a metal film, so thatconventional lead-based material can be used as the solder.

The terminal conductors 58 b are formed on the side surface 31 by theabove-described process, but since wiring pattern is not formednecessary on the side surface 31, there is a sufficient space. Inaddition, since only two pads for a lead line need to be provided on theside surface having a dimension of 6 mm×2 mm, the pad can be formed witha certain extent of dimension. Consequently, the lead lines can beeasily connected with solder or a conductive adhesive agent. And sincethe pad for a lead line is provided through a portion of the bar-shapeddevice, a reliable connection can be ensured without performingsimultaneous vapor deposition on the upper surface and the lower surfaceof the thermoelectric device block 53.

Incidentally, as other aspects are the same as those in the firstembodiment, the explanation thereof is omitted.

Fourth Embodiment of the Structure: FIG. 8, FIG. 10, and FIG. 19

Next, the fourth embodiment of the structure will be explained.Comparing to the first embodiment, a thermoelectric device according tothe present embodiment is different in that, as shown in FIG. 19, eachof bar-shaped devices 51 a, 52 a on at least one end portion and theother end portion out of an n-type and p-type bar-shaped devices 51, 52connected in series is exposed on one and the other portion of theopposing two side surfaces 37, 39 excluding interconnection terminalsurfaces 53 a, 53 b, and the structure is formed by bringing eachterminal conductor 58 b contact with each of the bar-shaped device 51 a,52 a on one end portion and the other end portion on the exposedsurface.

Though the terminal conductors 58 b formed on two side surfaces 37, 39are not connected to the interconnection conductors 58 a in theembodiment shown in the drawing, it can be possible to connect with eachother.

Incidentally, since other aspects are the same as those in the firstembodiment, the explanation thereof will be omitted.

Fifth Embodiment of the Method of Fabricating the Thermoelectric Device:FIG. 1 to FIG. 8, FIG. 10, FIG. 18 and FIG. 19

Next, the fifth embodiment of the method of fabricating thethermoelectric device will be explained. The present embodiment differsfrom the first embodiment in the following aspects. That is, before theprocess of forming the terminal conductor 58 b, provided is a process toexpose each of the bar-shaped devices 51 a, 52 a which are at least onone end portion and the other end portion out of the n-type and p-typebar-shaped devices 51, 52 connected in series on one and the other ofopposing two side surfaces 37, 39, and the forming process of theterminal conductor 58 b is such that a pair of the terminal conductor 58b is connected to each of the bar-shaped devices 51 a, 52 a which are onone end portion and the other end portion, on each exposed surface.

The process of forming the terminal conductor 58 b is carried out in amanner such that new side surfaces 37, 39 are formed by grinding orpolishing the opposing two side surfaces 53 d, 53 e so that each oneportion of the n-type bar-shaped devices 51 and p-type bar-shapeddevices 52 are exposed as shown in FIG. 18, and a predetermined metalmasking films are respectively brought to an intimate contact with thesetwo side surfaces and are fixed to form vapor deposition filmsrespectively. When carrying out the polishing or the like on the upperand lower surface of the thermoelectric device block 53 in the firstembodiment of the method of fabrication, a portion of the n-type andp-type bar-shaped devices can be exposed by polishing or the like theside surfaces 53 d, 53 e, or the upper and lower surfaces of thethermoelectric device block 53 can be polished after the above describedexposure process.

In the present embodiment, vapor deposition films are formed as a padfor a lead line, but the n-type and p-type bar-shaped devices exposed onthe side surfaces 37, 39 can be directly soldered without forming thevapor deposition films. However, since the bar-shaped devices are madeof BiTeSb-based material, the solder needs to be of the same sort.Therefore, it is desirable to form a metal film so that the solderingcan be performed with a conventional lead-based material.

Since interconnection patterns are not formed on the side surfaces 37,39, which ensures a sufficient space, and only one portion each isformed to provide the pad for a lead line on the side surface of thethermoelectric device block having 2.4 mm×2 mm in dimension, the pad canbe formed in a certain extent of dimension. Therefore, the lead line canbe easily connected by soldering and the like. In addition, since thepad for a lead line is formed through a portion of the bar-shapeddevices, a reliable connection can be secured without conducting asimultaneous vapor deposition of the upper and lower surfaces of thethermoelectric device block 53. When the terminal conductors 58 b areformed, the terminal conductor 58 b may be connected to theinterconnection conductor 58 a. Incidentally, since other aspects arethe same as those in the first embodiment, the explanation thereof willbe omitted.

Fifth Embodiment of the Structure: FIG. 8, FIG. 10, and FIG. 21

The fifth embodiment of the structure will be explained next. Thethermoelectric device in the present embodiment differs from thethermoelectric device in the first embodiment in that, as shown in FIG.21, the structure of the thermoelectric device block 53 is as follows.That is, each of chamfered oblique surfaces 33, 35 are formed between aside surface 53 c excluding the interconnecting end face and other sidesurfaces adjacent to both ends of the side surface 53 c, and each oneportion of the bar-shaped devices 51 a, 52 a at least on one end portionand the other end portion of the n-type bar-shaped devices connected inseries is exposed on each chamfered oblique surface 33, 35.

Incidentally, other aspects are the same as those in the firstembodiment, the explanation thereof will be omitted.

Sixth Embodiment of the Method of Fabricating the Thermoelectric Device:FIG. 1 to FIG. 8, FIG. 10, FIG. 20 and FIG. 21

The sixth embodiment of the method of fabricating the thermoelectricdevice will be explained next. Comparing to the first embodiment, thepresent embodiment differs in that another process is inserted beforethe process to form the terminal conductors 58 b, which is formed asfollows.

That is, before the step of forming the terminal conductors 58 b, thestep of forming chamfered oblique surfaces 33, 35 respectively wherebyto grind or polish two corner portions formed between the side surface53 c of the thermoelectric device block 53 and the side surfacesadjacent to the above-described both end, and the step of exposingportion of the bar-shaped device 51 a, 52 a which are at least on oneend portion and the other end portion of the n-type and p-typebar-shaped devices 51, 52 connected in series, on the chamfered obliquesurfaces 33, 35, are carried out. Then, following to these steps, apredetermined metal masking film is intimately contacted to the exposedportion of the chamfered oblique surfaces 33, 35, and fixed to form avapor deposition film, through which one and the other of a pair of theterminal conductor 58 b contact each bar-shaped device 51 a, 52 a.

The method of the vapor deposition and the vapor deposition film are thesame as those in the case of the side surface 53 c in the firstembodiment of the manufacturing method. However, when carrying out thevapor desposition, the side surface 53 c is covered with a mask havingno aperture.

In this embodiment, the vapor deposition film is formed as a pad for alead line, but without forming of the vapor deposition film, the n-typebar-shaped device 51 a or the p-type bar-shaped device 52 a exposed onthe side surfaces 33, 35 can be directly soldered. However, thedeposition of the metallic film is desirable because of the same reasonas in the case of the fourth embodiment of the manufacturing method.

When manufactured through this method, interconnection pattern is notformed on the side surface 53 c, which ensures a sufficient space. Inaddition, since the shape of the thermoelectric device block 53 is acuboid from which two corners are cut away, a compact thermoelectricdevice can be obtained without having a larger size than the initialcuboid due to a projection and the like made by soldering of a leadline.

Since the pad for a lead line is provided through a portion of thebar-shaped device, a reliable connection can be ensured without asimultaneous vapor deposition of the upper and lower surfaces of thethermoelectric device block 53.

Incidentally, since other aspects are the same as those in the firstembodiment, the explanation thereof will be omitted.

Next, as for a thermoelectric device to provide a terminal conductor onother surface excluding the upper surface 53 a and the lower surface 53b which serve as a interconnecting end face, another interconnectingpattern structure of the interconnection conductor 58 a of the n-typebar-shaped devices 51 and the p-type bar-shaped devices 52 will beexplained.

FIG. 22 shows a modified embodiment of the interconnection pattern ofthe upper surface 53 a shown in FIG. 9 and FIG. 23 shows a modifiedembodiment of the interconnecting pattern of the upper surface 53 ashown in FIG. 17, respectively. As shown in drawings, the thermoelectricdevice block 53 provides plural rows (three rows in FIG. 22) of thedevice row in which the n-type bar-shaped devices 51 and the p-typebar-shaped devices 52 alternately aligned. The interconnection conductor58 a in FIG. 22 consists of three types of the interconnectionconductors 58 a 1, 58 a 2, and 58 a 3.

The interconnection conductor 58 a 1 connects each end face of theadjacent n-type bar-shaped devices 51 and p-type bar-shaped devices 52contained in the same device row in the parallel direction in eachdevice row, and has a rectangular shape when seen from above. Theinterconnection conductor 58 a 2 is to transfer the interconnection tothe adjacent row, connecting each end face of the n-type bar-shapeddevices 51 and p-type bar-shaped devices 52 striding across the adjacentdevice row, and has a L-letter shape when seen from above. Theinterconnection conductor 58 a 3 has a pair of L-letter shapes when seenfrom above, which are connected to each of the end faces of bar-shapeddevices 51 a, 52 a at least on one end portion and the other end portionof the n-type and p-type bar-shaped devices 51, 52 connected in seriesby the interconnection conductor 58 a 1 and the interconnectionconductor 58 a 2.

In the present embodiment, a pair of terminal conductors 58 b which isformed on the side surface 53 c, is electrically connected respectivelyto the interconnection conductor 58 a 3 on the edge portion of the uppersurface 53 a. Accordingly, the n-type and p-type bar-shaped devices 51,52 are connected in series by the interconnection conductor 58 a 1 andthe interconnection conductor 58 a 2, and the interconnection conductor58 a 3 is connected to each end face of bar-shaped devices 51 a, 52 aprovided on one end face and the other end face, and in addition, theterminal conductor 58 b is connected to each interconnection conductor58 a 3, so that voltage can be effectively taken out in one side surfaceby connecting a desired lead wire to each terminal conductor 58 b. Theterminal conductors 58 b in the present embodiment is formed on one sidesurface 53 c, but the terminal conductors 58 b can be formed to twoopposing side surfaces respectively adjacent to the side surface 53 c.

Next, the interconnection pattern shown in FIG. 23 will be explained.The pattern has a plurality of device rows (four rows) similar to thatin FIG. 22, consisting of three interconnection conductors 58 a whichare 58 a 1, 58 a 2, and 58 a 3. Since the interconnection conductors 58a 1, 58 a 2 are the same as those in FIG. 22, the explanation thereofwill be omitted. The interconnection conductor 58 a 3 has a pair ofL-letter shapes when seen from above, which is connected to each endface of the first bar-shaped device group containing the bar-shapeddevice 51 a at least on one end portion, and each end face of the secondbar-shaped device group containing the bar-shaped device 52 a on theother end portion of the n-type and p-type bar-shaped device 51, 52connected in series by the interconnection conductor 58 a 1 and theinterconnection conductor 58 a 2. Each of a pair of terminal conductors58 b is formed on the exposed surface of the bar-shaped device so as tocontact the bar-shaped device 51 a contained in the first bar-shapeddevice group, and the bar-shaped device 52 a contained in the secondbar-shaped device group, with the bar-shaped device exposed on the sidesurface 53 c of the thermoelectric device block 3. In the case of thepresent embodiment, by connecting a desired lead wire to each terminalconductor 58 b similar to the case in FIG. 22, voltage can beeffectively taken out on one side surface.

The terminal conductor 58 b may be formed one each on two opposing sidesurfaces adjacent to the side surface 53 c, or as shown in the drawing,not only the case of no contacting the interconnection conductor 58 a 3,but can be formed so as to make contact therewith.

Other interconnection patterns are shown in FIG. 24 and FIG. 25. Bothpatterns have a plurality of device rows (three rows in FIG. 24, andfour rows in FIG. 25), and the interconnection conductor 58 a consistsof three interconnection conductor 58 a, that is, 58 a 1, 58 a 2, and 58a 3. Incidentally, FIG. 24 corresponds to the modified embodiment inFIG. 22, and FIG. 25 corresponds to the modified embodiment in FIG. 23.What FIG. 24 and FIG. 25 differ from FIG. 22 and FIG. 23 is that each ofthe bar-shaped devices 51 a, 52 a provided on one end portion and theother end portion of the n-type and p-type bar-shaped devices 51, 52connected in series is disposed near the diagonal positions of thethermoelectric device block 3. Even in these cases, by connecting adesired lead wire to each terminal conductor 58 b, voltage can beeffectively taken out from one side surface. As for each terminalconductor 58 b, in the case shown in FIG. 24, both of the terminalconductors are connected to the interconnection conductor 58 a 3 on theside surface 53 c, but one each can be formed on two opposing sidesurfaces adjacent to the side surface 53 c. In the case shown in FIG.25, the terminal conductor is formed without contacting theinterconnection conductor 58 a 3, but can be formed in contact with theinterconnection conductor 58 a 3.

The interconnection patterns shown in FIG. 24 and FIG. 25 have been longconsidered, but since each of the bar-shaped devices 51 a, 52 a on oneend portion and the other end portion of the n-type bar-shaped device 51and the p-type bar-shaped device 52 alternately connected in series inthis interconnection pattern is disposed near the diagonal position ofthe thermoelectric device block 3, the lead wire can be taken out fromonly the two side surfaces.

Then, in the present invention, as shown in the drawings, twointerconnection conductors 58 a 3 in the final position of theinterconnection to connect with a pair of terminal conductors 58 b aremade in an asymmetrical shape so as to make contact with each of thebar-shaped devices 51 a, 52 a near the diagonal position so that thedrawing out from one side surface 53 c is made possible.

The interconnection pattern shown in FIG. 22 to FIG. 25, differing fromthe above described interconnection pattern, has no such a pattern thatobliquely connects between the bar-shaped device rows. Therefore, evenwhen distance between the bar-shaped devices becomes small accompanyingby micronizing the thermoelectric device, the interconnection patterndoes not become too fine, which makes it useful.

It should be noted that a conductor having a L-letter shape is used asan example to transfer the interconnection to the adjacent row in thisexplanation, but since the essential function is to make contact withthe adjacent row, any pattern that can perform the function (to connectcrossing over the adjacent n-type bar-shaped device 51 and the p-typebar-shaped device 52) may be acceptable, even if it is in a square or atriangle shape, other than a L-letter shape.

INDUSTRIAL APPLICABILITY

As clear from the above explanation, a thermoelectric device of thepresent invention can efficiently take out voltage in spite of itsminute size. According to a method of fabrication of the presentinvention, the thermoelectric device is to take out a lead line from aside surface on which electrode pattern is not formed, so that the leadline can be connected with an easy operation.

In addition, since a new section is not required for taking out the leadline, a small space can be utilized more efficiently, and thethermocouples can be housed in high density. Accordingly, it can beinstalled into a fine device such as a wrist watch.

Using the thermoelectric device of the present invention, electricgeneration by temperature difference will maybe utilized in a portableelectronics device such as a wrist watch.

Additionally, a small high performance cooling apparatus can be preparedusing the thermoelectric device, which is extremely useful as a portablerefrigerator or a local cooling apparatus for a laser or an integratedcircuit.

What is claimed is:
 1. A method of fabricating a thermoelectric device,comprising the steps of: forming a thermoelectric device block havingtwo faces of interconnecting end faces by regularly disposing and fixinga plurality of n-type bar-shape devices consisting of the n-typethermoelectric semiconductors and a plurality of p-type bar-shapeddevices consisting of the p-type thermoelectric semiconductors throughan insulating layer, and exposing respectively both end faces of saideach n-type bar-shaped device and each p-type bar-shaped device; forminga plurality of thermoelectric couples by connecting between end faces ofsaid n-type bar-shaped device and p-type bar-shaped device with aninterconnection conductor on the interconnecting end face of thethermoelectric device block, and connecting alternatively said pluraln-type bar-shaped devices and plural p-type bar-shaped devices inseries; and forming a pair of terminal conductors electrically connectedrespectively to the bar-shaped devices at least on one end portion andthe other end portion of said plural thermocouples connected in series,on a face excluding said interconnecting end face of said thermoelectricdevice block.
 2. The method of fabricating the thermoelectric deviceaccording to claim 1, wherein said pair of terminal conductors is formedon one face excluding said interconnecting end face of saidthermoelectric device block in said step of forming the terminalconductor.
 3. The method of fabricating the thermoelectric deviceaccording to claim 1, wherein said pair of terminal conductors is formedone each on opposing two faces excluding said interconnecting end facesof said thermoelectric device block in said step of forming the terminalconductor.
 4. The method of fabricating the thermoelectric deviceaccording to claim 1, further comprising the steps of: exposing eachbar-shaped device at least on one end portion and the other end portionof a plurality of said thermocouples connected in series on one faceexcluding said interconnecting end face of said thermoelectric deviceblock, before said step of forming the terminal conductor; and formingsaid terminal conductor by making contact respectively with one and theother of said pair of terminal conductor on the exposed surface of saideach bar-shaped device in said step of forming the terminal conductor.5. The method of fabricating the thermoelectric device according toclaim 1, further comprising the steps of: exposing each bar-shapeddevice at least on one end face and the other end face of plural saidthermocouples connected in series on one and the other of opposing twosurfaces excluding said interconnecting end face of said thermoelectricdevice block, before said step of forming the terminal conductor; andforming said terminal conductor by bringing one and the other of saidpair of terminal conductors respectively into contact with the exposedsurfaces on said one face and the other face of said each bar-shapeddevice in said step of forming the terminal conductor.
 6. The method offabricating the thermoelectric device according to claim 1, furthercomprising the steps of: forming respective chamfered oblique faces bygrinding or polishing a corner formed with one face excluding saidinterconnecting end face of said thermoelectric device block and eachface adjacent to both ends of said face, and exposing respectively eachbar-shaped device at least on one end portion and the other end portionof said thermocouples connected in series on the one chamfered obliqueface and the other chamfered oblique face before said step of formingthe terminal conductor; and forming the thermoelectric device bybringing one and the other of said pair of terminal conductors contactwith the exposed surface on said one chamfered oblique face and theexposed surface on the other chamfered oblique face of said eachbar-shaped device in said step of forming the terminal conductor.
 7. Themethod of fabricating the thermoelectric device according to any one ofclaim 1 to claim 6, wherein the process of forming said thermoelectricdevice block comprises the steps of: forming a longitudinal groove and alongitudinal partition wall respectively on the n-type thermoelectricsemiconductor block and the p-type thermoelectric semiconductor block tomake an n-type grooved block and a p-type grooved block; unifying then-type grooved block and p-type grooved block by fixing saidlongitudinal groove and longitudinal partition wall each other tocombine and forming an insulating adhesive layer in the space betweenthe fixed portion of both blocks to make an integrated block; making anintegrated grooved block by forming a transverse groove and a transversepartition wall in the direction intersecting to said longitudinal grooveon the integrated block; forming a block by making an insulating layeron the transverse groove of the integrated grooved block and regularlydisposing said plural n-type bar-shaped device and said plural p-typebar-shaped device through the insulating layer; and forming two faces ofinterconnecting end faces exposed both end faces of said each n-typebar-shaped device and each p-type bar-shaped device by grinding andpolishing two surfaces intersecting at right angles with thelongitudinal direction of said each n-type bar-shaped device and p-typebar-shaped device of said block.